In a review of the HP Compaq dc7800 published in IT Week today, I measured the power consumption of this compact new desktop PC to see if it used less energy than rival systems. It did just that, using a maximum 78W in our tests, whereas a standard system can easily top 200W.

However, I was surprised to see just how  much energy the system used even when it was switched off. Just connected to the mains, the dc7800 and its mains adapter consumed over 9W. Multiplied across a building full of PCs, this might add up to a considerable waste of energy overnight and at the weekend, even if users respond to calls to turn their system off before they leave work.

And this is in a system designed for power efficiency. A standard mini-tower PC I measured was found to consume at least 21W when turned off.

However, as I pointed out in the print review of the HP system, it is not practicable for most businesses to introduce a policy of unplugging equipment when not in use, because IT departments need to able to remote boot systems for after-hours maintenance and updates.

Is there anything that enterprises can do to reduce this waste of power, or is it all down to the equipment manufacturer to design kit to be as efficient as possible, even when in the off state?

03 Dec 2007